Corrugated stacked-plate heat exchanger



7 Jan. 28, 1969 w. J.STE|N ET AL Filed Au 26, 1966 INVENTORS.

Nm N EA m .3 J 6% O T A V L L O A W S Big/h ATTORNEYS.

Jan. 28, 1969 w. J. STEIN ET Al- CORRUGATED STACKED-PLATE HEAT EXCHANGER Filed Aug. 2a., 1966 INVENTORS Wm E EN N TA R S O T J. M E MR A G M L A WS VI Jan. 28, 1969 w. J. STEIN ET AL 3,424,240 7 CORRUGATED STACKED-PLATE HEAT EXCHANGER Sheet Filed Aug. 26, 1966 INVENTORS.

II S .CIBA E S m H N J P m T NR. A

United States Patent 3,424,240 CORRUGATED STACKED-PLATE HEAT EXCHANGER Wolfgang J. Stein, Milford, and Salvatore Straniti, Orange, C0nn., assignors to Avco Corporation, Stratford, Conn, a corporation of Delaware Filed Aug. 26, 1966, Ser. No. 575,285 U.S. Cl. 165-166 11 Claims Int. Cl. F28f 3/04, 13/06 ABSTRACT OF THE DISCLOSURE Plates of relatively thin material are formed in series one and series two types for stacking alternately in construction pairs, with patterns of corrugations between spaced openings in the stacked plates. Alternate plates in each stack providing corrugated patterns with transverse relationship assuring turbulence-inciting structure in both primary and secondary flow passages. Pairs of plates are sealed together to form construction pairs which pairs are secured together to complete the structure of the stack accomplished by sealing only two surfaces of substantially uniform thickness of plate. The construction of the stack of plates is accomplished without necessity for provision of tubular inlet and outlet channels extending through the stack.

This invention relates to a corrugated plate-type heat exchanger.

Heat exchange devices made up of a plurality of plates of relatively thin material, so formed and stacked as to provide heat transfer through said plates to and from a series of alternate primary and secondary flow passages formed between alternate plates so stacked, are known generally in the art.

The improvements accomplished by the disclosure, herein constituting objects of the invention, include:

Plates formed in series one and series two types for stacking alternately in construction pairs to form the stack;

Plates formed with patterns of corrugations between spaced openings in the stacked plates extending across said plates, providing complementing channel-forming wave formations for fluid flow across the plates with ad ditional formations on series one and series two plates providing surface contact adjacent the openings to form construction pairs of plates by sealing surfaces around the openings;

Alternate plates in said stack providing corrugated patterns with transverse relationship of such corrugations on each of the facing plates in said stack, thereby providing turbulence-inciting transverse relationship of corrugations in both primary and secondary flow passages;

Formations on series one and series two plates affording displaced planar surfaces on the edges of the plates to connect together construction pairs by sealing the edges of said plates;

' Means to seal pairs of plates together to form construction pairs and to seal construction pairs together to complete a stacked series of plates with alternate primary and secondary flow passages, the sealing accomplished by sealing only surfaces of two uniform thicknesses of plate while accomplishing the definition and confinement of alternate primary and secondary flow passages with inlet and outlet thereto with no additional inlet and outlet conduit within the stack;

Means to seal in aforesaid structure accomplished by welding or brazing of plates of uniform thickness as the sole connecting means for completing such assembly.

The aforesaid plate structure enables a stacked-plate construction to be assembled together with the joints in said assembly accomplished solely by welding or brazing of two plate surfaces contacting each other with such plate surfaces formed from two plates of uniform thickness, thereby limiting the internal stresses in said structure resulting from growth of the metal during wide range of temperature variation; such structure and means of assembly also obviating the necessity for tubular inlet and outlet channels extending longitudinally of the stack and, further, without necessity for provision in the stack of connections and inlet and outlet openings from such tubes to and from heat transfer channels in the stack.

The above and other objects of the invention will appear more fully from the following more detailed description and by reference to the accompanying drawings forming a part hereof and wherein:

FIGURE 1 is a perspective view of a plate-type heat exchange device made up of a plurality of stacked plates annular in form and providing for heat transfer from a high-temperature fluid flow, which might flow inward or outward through the stack, but here shown as an exhaust gas from the center annular region, flowing outward through alternate plates of the stack and transferring heat through the plates to secondary fluid flow between alternate plates in the stack.

FIGURE 2 is a gas turbine engine schematic wherein the position of the stacked-plate heat exchange unit is indicated in diagrammatic form as related to the fluid flow through a gas turbine engine.

FIGURE 3 is an end view, cross section, partly broken away, of the stacked-plate heat exchange device substantially like that shown in FIGURES 1 and 2 as it may be installed in an engine with certain regions of the plates broken away to show the relative positioning of passageways in the plates formed by corrugation patterns and further formations in the plates providing for stacking and forming primary and secondary flow passages through the plate stack.

Referring to the drawings and particularly to FIGURE 1, a multiplicity of plates 10 of relatively thin material make up a stack 12, forming the heat exchange unit of generally annular form, shown in FIGURE 1. Such unit is particularly adapted for use as a regenerator for a gas turbine engine, which is an illustrative embodiment of the heat exchange device of this invention.

Also referring to FIGURE 1, a primary fluid-flow passage 14 centrally of the annular stack is provided. Such fluid flow might be the hot exhaust gases from a power plant, such as a gas turbine engine. The heavy line arrows of FIGURE 1 show the flow of hot gases from the central flow passage 14 continuing radially outward between alternate plates of the stack 12 to the outside of the stack in primary flow passages 15. Heat transfer is thus accomplished from primary fluid-flow passages through the one thickness of the plates 10 into adjacent alternate secondary fluid-flow passages 16. These secondary fluidflow passages 16 are, in this illustration, for the air flow from the compressor of the engine entering the stack through inlet openings 18 and passing through the secondary fluid-flow passage 16 to alternate outlets 20. The multiplicity of secondary fluid-flow passages 16 alternates with primary fluid-flow passages 15 between alternate plates and thus effect the heat transfer through the single plate thicknesses as aforesaid. In the diagrammatic showing of FIGURE 1 the thin arrow lines represent flow into the spaced inlet openings 18, while the dotted arrow lines indicate outlet flow through the alternate outlet openings 20 in each plate. It is noted that inlet 18 and outlet 20 openings through the plate alternate circumferentially around each annular plate and are aligned in the stack. There are two types of plates provided, series one 10a and series two 1%, each of which have spaced inlets and outlets aligned in the stack as aforesaid and one of each 10a and 10b plates are secured together to form construction pairs 11 which are stacked together to form the stack 12. The series one a and series two 10b plates differ as to the formations and patterns on the plates, i.e., the series one plates 10a are provided with a pattern of corrugations 24 extending in the generally radial direction from the inner edge 26 of the annular plate 10a to the outer edge 28 thereof and providing complementing channel-forming wave formations 24 from adjacent the inner edge 26 to adjacent the outer edge 28 on the surfaces of said series one 10a plates, said radially extending corrugation patterns being repeated between each inlet 18 and outlet 20 openings circumferentially around each annular plate 10a.

The series two 10b plates in the stack, which are alternate with the 10a series one plates throughout the stack, have corrugation patterns 38 extending in a generally circumferential direction between inlet and outlet openings 18 and 20 formed to provide connection between said spaced openings on one side of each plate but affording corrugation patterns on both sides of each 1% plate located between all its spaced openings 18 and 20.

Formations 32 on said series one 100 plates and formations 34 on series two 1012 plates are so positioned and arranged that their resulting surfaces adjacent said openings 18 and 20 are in surface contact for securing a series one 10a and a series two 10b plate together to form the aforesaid construction pair 11, a multiplicity of which construction pairs 11 are stacked together to form said stack 12. Each aforesaid construction pair 11 is formed by sealing said surfaces of formations 32, 34 around said openings 18 and 20.

It is noted that said series two 11)!) plates are formed with generally parallel corrugations 38 formed in patterns between each of the aforesaid spaced openings 18 and 20 of said plates, but the said corrugation 38 patterns, so formed, provide connection between said spaced openings only on the side of said series two 10b plates facing outward in each said construction pair 11, and that the major portion of said corrugations 38 extend transversely to the radially extending corrugation pattern 24 in the mating series one 10a plate.

Further formations are provided on series one 10a and series two 10b plates affording displaced formations of circumferential planar surfaces 54, 56 outside and 54a, 56a inside on each of the edges of series one 10a and series two 10b plates, so relatively .positioned and arranged that the circumferential edge surface 54, 54a of each series one 10a plate of a pair 11 in the stack 12 will make surface contact with the edge surface 56, 56a of a series two 10b plate of an adjacent pair in the stack in such position that said contacting edge surfaces may be sealed to complete a stack 12 of such pairs 11 secured together as aforesaid. The corrugation patterns of the facing series one 10a and series two 1% plates in each construction pair 11, while serving to direct and confine primary transverse heat-transfer fluid passages 15 between the plates of said stacked construction pairs 11 extending transversely through said stack, also provide the aforesaid transverse relationship of corrugation patterns 24, 38 on such facing plates, the transverse corrugation inciting desired turbulence in the primary flow channel. The facing formed patterns 24, 38 of adjacent series one 10a and series two 10!) plates of adjacent stacked construction pairs 11 serve to direct and confine secondary heat-transfer passages 16 formed between said pairs 11 which are secured together by sealing adjacent edges 54, 56 as aforesaid. The inlet 18 and outlet 20 to said secondary flow heat-transfer passages 16 are afforded between alternate plates in said stack by the said aligned inlet 18 and outlet 20 openings extending longitudinally of such stack. The transverse corrugation patterns 38 on the opposite faces of said series two 10b plates afford secondary flow passages 16 between said inlet 18 and outlet 20 to the longitudinal passages formed by the aligned openings 18 and 20 and with each facing plate of adjacent series one 10a plate in adjacent pairs providing corrugations 24 transverse to corrugations 38 for inciting desired turbulence in said secondary flow heat-transfer passages 16.

It is noted that the stacked plates, formed and positioned together as above described, may be satisfactorily welded at the contacting surfaces around the inlet and outlet openings 18 and 20 and around the circumferentially contacting surfaces 54, 54a, 56, 56a by means of electrical-resistance welding (or other securing means) and when so secured will result in a unit made up of plates of uniform thickness and with all the welds accomplished by the securing together of only two plates of uniform thicknesses, thereby obviating objectionable stresses often incurred by heat changes when relatively thin plates are secured to other surfaces of tubes or other parts of substantially greater thickness.

It is also to be noted that the inlet and outlet channels in the stack for the secondary flow is accomplished solely by the openings 18, 20 in the stacked plates and no tubes are required to complete these connections inasmuch as flow into alternate secondary flow channels between the plates is completed by the openings 18, 20 themselves when the entire pack is secured together as hereinabove described.

The primary flow is through the stack from the inner annular edge surface to the outer circumferential edge surface of the stack and therefore requires no inlet and outlet connections contacting the plates of the stack.

The provision of series one 10a plates and series two 18b plates, which when stacked together have corrugations substantially transverse to each other on the facing surfaces of plates forming the alternate primary flow and secondary flow channels, assures both a heat transfer through a single thickness of plate with inlet and outlet to both primary and secondary flow channels accomplished by formations in the plates while affording also in each of the flow channels a transverse relationship of facing corrugations inciting turbulent flow in both the heat transfer regions and channels, thereby increasing the efficiency ofheat transfer by retarding and distributing the flow in said channels.

Referring to FIGURE 2, the diagrammatic showing is an illustration of the arrangement using the plate stack 12 of the type shown in FIGURE 1 as the regenerator for a gas turbine engine. The annular plate stack 12 is assembled in the rearward section 60 of the engine and the annular central region 14 is rearward of the turbine section 62 of the engine so that the hot exhaust gases from the turbine section 62 flow radially through the stack, as shown by the heavy black arrows, the flow being through alternate primary fluid-flow passages 15 between alternate plates in the stack previously mentioned in the description of FIGURE 1. Also to designate the arrangement relative to the inlets 18 and outlets 20 through the stack, corresponding numbers in this drawing indicate the fiow through the alternate secondary flow passages 16 in alternate relationship to the primary flow passages 15 so that the heat transfer between the plates in the stack is accomplished and the inlets 18 take the air from the compressor region 64 of the engine into the heat exchanger and out the outlets 21) to the com-buster region 66 of the engine and thence into the turbine region when mixed with fuel in the combustion region 66 and into the turbine section 62 of the engine. It is understood that flow from compressor 64 to inlets 18 is accomplished by suitable annular manifold, not shown, to reach the multiplicity of annularly spaced inlets in the stack and, likewise, another annular manifold collects flow from the multiple number of outlets 20 from the stack 12 to carry the heated air to the combustor 66, as shown.

Referring to FIGURE 3, there is shown an end view, partly in section and partly broken away, of a stacked plate assembly 12 wherein such assembly is shown supported in a container 70 of generally cylindrical form with an outlet 71 at the top and an outlet 72 at the bottom. The stacked plate assembly 12 is supported in the container 70, the assembly 12 being spaced from the outer walls of the container by suitable supports 73, a plurality of which are shown in FIGURE 3. When so supported the exhaust gases from an engine to which this assembly might be attached, such as engine shown in FIGURE 2, such exhaust gases will go through the alternate primary flow passages 15 radially outward to provide heat transfer to the alternate regions 16 in the plate arrangement. The series of inlet openings 18 and outlets 20 are also shown in FIGURE 3 as well as with corrugation patterns 24 and 38 on alternate plates a (radial corrugations), 10b (transverse corrugations) in the stack thus providing corrugation patterns transverse to each other, as in the description of the structure of FIGURE 1. The entire unit is thus supported in the container 70 with upper exhaust outlet 71 and lower exhaust outlet 72 as shown in FIGURES 2 and 3.

It is understood that various modifications are contemplated in this unit and without limitation it is to be emphasized that exhaust gas movement or so-called primary flow could be accomplished through the stacked plate assembly either radially outward as shown or radially inward by change in structure of the surrounding container and related passageways so that the exhaust would finally pass either from the center region 14 or from a circumferential region depending on flow direction.

It is contemplated that various means of securing the plates together at the contacting regions of the formations 32, 34 and 54, 54a and 56, 56a might be used, welding or brazing being specifically mentioned in this disclosure.

The invention having been described by reference to a specific structure, it is understood that various modifications are intended within the scope of the following claims.

We claim:

1. A heat exchange device made up of a plurality of plates of substantially uniform planar extent and of relatively thin material so formed and stacked as to provide heat transfer through said plates to and from a series of alternate primary and secondary fluid flow passages formed between alternate plates so stacked;

said plates formed in series one and series two types for stacking alternately in construction pairs to form said stack;

said plates having spaced openings therein aligned when stacked to form inlet and outlet to and from one of said series of flow passages in a direction longitudinally of said stacked plates;

said series one plates formed with a pattern of corrugations between said spaced openings extending across said plates and providing complementing channelforming generally parallel wave formations on both surfaces of said series one plates;

said series two plates formed with a pattern of generally parallel corrugations forming a pattern between the aforesaid spaced openings on both sides of said plates but with said pattern formed with said corrupations extending transversely to the corrguations in said series one plates on both sides of said plate when a series one plate and a series two plate are positioned together to form a construction pair with the said spaced openings in alignment.

2. A heat exchange device made up of a plurality of plates of substantially uniform planar extent and of relatively thin material so formed and stacked as to provide heat transfer through said plates to and from a series of alternate primary and secondary fluid flow passages formed between alternate plates so stacked;

said plates formed in series one and series two types for stacking alternately in construction pairs to form said stack;

said plates having spaced openings'therein aligned when stacked to form inlet and outlet to and from one of said series of flow passages in a direction longitudinally of said stacked plates;

said series one plates formed with a pattern of corrugations between said spaced openings extending across said plates and providing complementing channelforming wave formations from adjacent one edge to adjacent the other edge on both surfaces of said series one plates;

said series two plates formed with generally parallel corrugations forming a pattern between the aforesaid spaced openings of said plates but with said pattern formed to provide connection between said spaced openings on the side of said series two plate facing outward in said construction pair and with the major portion of said corrugations extending transversely to the corrugations in said series one plates on both sides of said plate when a series one plate and a series two plate are positioned together to form a construction pair with the said spaced openings in alignment.

3. A heat exchange device made up of a plurality of plates of substantially uniform planar extent and of relatively thin material so formed and stacked as to provide heat transfer through said plates to and from a series of alternate primary and secondary fluid flow passages formed between alternate plates so stacked;

said plates formed for stacking alternately in construction pairs to form said stack;

said plates having spaced openings therein aligned when stacked to form inlet and outlet to and from one of said series of flow passages in a direction longitudinally of said stacked plates; formations on said plates adjacent spaced inlet openings in said plates so positioned and arranged that surfaces adjacent said openings are in surface contact for securing plates together to form each said construction pair by sealing said surfaces around said openings;

further formations provided on plates affording a displaced planar surface on the edges of plates so relatively positioned and arranged that the edges of plates of pairs in the stack will make surface contact with the edges of plates in adjacent pairs in the stack in such position that said contacting edges may be sealed to complete a stack of such pairs secured together as aforesaid;

said series one plates formed with a pattern of corrugations between said spaced openings extending across said plates and providing complementing channelfor-ming generally parallel wave formations on both surfaces of said series one plates;

said series two plates formed with a pattern of generally parallel corrugations forming a pattern between the aforesaid spaced openings on both sides of said plates but with said pattern formed with said corrugations extending transversely to the corrugations in said series one plates on both sides of said plate when a series one plate and a series two plate are positioned together to form a construction pair with the said spaced openings in alignment.

4. A heat exchange device made up of a plurality of plates of substantially uniform planar extent and of relatively thin material so formed and stacked as to provide heat transfer through said plates to and from a series of alternate primary and secondary fluid-flow passage-s formed between alternate plates so stacked;

said plates formed in series one and series two types for stacking alternately in conlstruction pairs to form said stack;

said plates having spaced openings therein aligned when stacked to form inlet and outlet to and from one of said series of fiow passages in a direction longitudinally of said stacked plates;

formations on said series one and series two plates adjacent spaced inlet openings in said plates so positioned and arranged that surfaces adjacent said openings are in surface contact for securing a series one and a series two plate together to form each said construction pair by sealing said surfaces around said openings;

further formations provided on series one and series two plates affording a displaced circumferential planar surface on the edges of series one and series two plates so relatively positioned and arranged that the circumferential edge of each series one plate of pairs in the stack will make surface contact with the edge of a series two plate of an adjacent pair in the stack in such position that said contacting edges may be sealed to complete a stack of such pairs secured together as aforesaid.

5. A heat exchange device made up of a plurality of plates of substantially uniform planar extent and of relatively thin material, so formed and stacked as to provide heat transfer through said plates to and from a series of alternate primary and secondary fluid-flow passages formed between alternate plates so stacked;

said plates having spaced openings therein aligned when stacked to form inlet and outlet to and from one of said series of flow passages in a direction longitudinally of said stacked plates;

said plates formed in series one and series two types for stacking alternately in construction pairs to form said stack; said series one plates formed with a pattern of corrugations between said spaced openings extending across said plates and providing complementing channel-forming wave formations from adjacent one edge to adjacent the other edge on both surfaces of said series one plates; said series two plates formed with generally parallel corrugations forming a pattern between the aforesaid spaced openings in said plates but with said pattern formed to provide connection between said spaced openings on the side of said series two plates facing outward in each said construction pair and with the major portion of said corrugations extending transversely to the corrugation in said series one plates on both sides of said plate when a series one plate and a series two plate are positioned together to form a construction pair with said spaced openings in alignment; said corrugation patterns of said facing series one and series two plates in each construction pair serving to direct and confine primary transverse heat-transfer-fluid passageways between the plates of said stacked construction pairs transversely through said stack with the aforesaid transverse relationship of corrugation patterns on such facing plate providing transverse corrugations for inciting turbulence;

facing forme'd patterns of adjacent series one and series two plates of adjacent construction pairs serving to direct and confine secondary heat-transfer passages formed between said pairs thus secured together by sealing the adjacent edges as aforesaid; and

said transverse corrugation patterns in said series two plates affording secondary flow between said inlets and said outlets to the longitudinal passages formed by said aligned openings and with each facing plate of the adjacent series one plate in adjacent pairs providing transverse corrugations for inciting turbulence in said secondary flow heat-transfer passages.

6. A heat exchange device made up of a plurality of plates of substantially uniform planar extent and of relatively thin material so formed and stacked as to provide heat transfer through said plates to and from a series of alternate primary and secondary fluid-flow passages formed between alternate plates so stacked;

said plates having spaced openings therein aligned when stacked to form inlet and outlet to and from one of said series of flow passages in a direction longitudinally of said stacked plates;

said plates formed in series one and series two type for stacking alternately in construction pairs to form said stack;

inlet and outlet to said secondary flow heat-transfer passages afforded between alternate plates in said stack by the aligned inlet and outlet openings extending longitudinally of said stack;

thereby forming said inlet and outlet passages longitudinally through the stacked plates solely by the said aligned openings in said plates;

said series one plates for-med with a pattern of corrugations betw en said spaced openings extending across said plates and providing complementing channel-forming generally parallel wave formations on both surfaces of said series one plates;

said series two plates formed with a pattern of generally parallel corrugations forming a pattern between the aforesaid spaced openings on both sides of said plates but with said pattern formed with said corrugations extending transversely to the corrugations in said series one plates on both sides of said plate when a series one plate and a series two plate are positioned together to form a construction pair with the said spaced openings in alignment.

7. A heat exchange device made up of a plurality of plates of substantially uniform planar extent and of relatively thin material, so formed and stacked as to provide heat transfer through said plates to and from a series of alternate primary and secondary fluid flow passages formed between alternate plates so stacked;

said plates having spaced openings therein aligned when stacked to form inlet and outlet to and from one of said series of flow passages in a direction longitudinally of said stacked plates;

said plates formed in series one and series two types for stacking alternately in construction pairs to form said stack;

formations on said series one and series two plates adjacent spaced inlet openings in said plates so positioned and arranged that surfaces adjacent said openings are in surface contact for securing a series one and a series two plate together to form each construction pair in said stack by sealing said surfaces around said openings;

further formations provided in series one and series two plates affording displaced circumferentially planar surface on the edges of series one and series two plates, so relatively positioned and arranged that the circumferential edge of each series one plate of pairs in the stack will make surface contact with the edge of a series two plate of an adjacent pair in the stack in such position that contacting edges may be sealed to complete a stack of such pairs secured together as aforesaid;

said sealing of surfaces around said openings and sealing of surfaces on said contacting edges completed by welding, thereby providing a structural assembly of said stacked plates uniformly secured together by joining two plates of uniform thickness.

8. A heat exchange device made up of a plurality of plates of substantially uniform planar extent and of relatively thin material, so formed and stacked as to provide heat transfer through said plates to and from a series of alternate primary and secondary fluid-flow passages formed between alternate plates so stacked;

said plates having spaced openings therein aligned when stacked to form inlet and outlet to and from one of said series of fiow passages in a direction longitudinally of said stacked plates;

said plates formed in series one and series two types for stacking alternately in construction pairs to form said stack;

said plates formed with a pattern of corruglations between said spaced openings extending across said plates and providing complementary channel-forming wave formations from adjacent one edge to adjacent the other edge of both surfaces of said series one viding transverse corrugations for inciting turbulence in said secondary flow heat-transfer passages. 11. A heat exchange device made up of a plurality of said plates formed in series one and series two types for stacking alternately in construction pairs to form said stack;

said series one plates formed with a pattern of corrugations between said spaced openings extending plates; across said plates and providing complementing formations on said series one and series two plates channel-forming wave formations from adjacent one adjacent spaced inlet openings in said plates, so posiedge to adjacent the other edge on both surfaces of tioned and arranged that surfaces adjacent said opensaid series one plates; ings are in surface contact for securing a series one formations on said series one and series two plates adand a series two plate together to form each said jacent spaced inlet andoutlet openings in said plates construction pair by sealing said surf-aces around said so positioned and arranged that surfaces adjacent said openings; openings are in surface contact for securing a series said series two plates formed with generally parallel one and a series two plate together to form each said corrugations forming a pattern between the aforeconstruction pair by sealing said surfaces around said said spaced openings of said plates but with said patopenings; tern formed to provide connection between said said series two plates formed with generally parallel spaced openings on the side of said series two plate corrugations forming a pattern between the aforesaid facing outward in each said construction pair and spaced openings of said plates but said pattern formed with the major portion of said corrugations extending to provide connection between said spaced openings transversely to the corrugation in said series one on the side of said series two plate facing outward plates on both sides of said plate when a series one in said construction pair and with the major portion plate and a series two plate are positioned together of said corrugations extending transversely to the to form a construction pair with the said spaced corrugations in said series one plates on both sides openings in alignment. of said plate when a series one plate and a series two 9. A heat exchange device as in claim 8 in which: plate are positioned together to form a construction further formations are provided on series one and series pair with the spaced openings in alignment;

two plates affording a displaced circumferential further formations on series one and series two plates planar surface on the edges of series one and series providing a displaced circumferential planar surface two plates so relatively positioned and arranged that on the edges of series one and series two plates so the circumferential edge of each series one plate of relatively positioned and arranged that the circumpairs in the stack will make surface contact with the ferential edge of each series one plate of a pair in edge of a series two plate of an adjacent pair in the the stack will make surface contact with the edge of stack in such position that said contacting edges may a series two plate of an adjacent pair in the stack in be sealed to complete a stack of such pairs secured such in such position that said contacting edges may together as aforesaid; be sealed to complete a stack of such pairs secured said corrugation patterns of said facing series one and together as aforesaid;

series two plates in each construction pair serving to said corrugation patterns of said facing series one and direct and confine primary transverse heat-transfer series two plates in each construction pair serving to fluid passageways between the plates of said stacked direct and confine primary transverse heat-transfer construction pairs transversely through said stack fluid passageways between the plates of said stacked with the aforesaid transverse relationship of the corconstruction pairs transversely through said stack rugations pattern on such facing plates providing with the aforesaid transverse relationship of the cortransverse corrugations for inciting turbulence; rugation pattern on such facing plates providing and the facing formed patterns of adjacent series one transverse corrugations for inciting turbulence;

and series two plates of adjacent construction pairs and said facing formed patterns of adjacent series one serving to direct and confine secondary heat-transfer and series two plates of adjacent pairs serving to passages formed between said pairs thus secured todirect and confine secondary heat-transfer passages gether by sealing the adjacent edges as aforesaid. formed between said pairs thus secured together by 10. A heat exchange device as provided in claim 9 in sealing the adjacent edges as aforesaid; which: inlet and outlet to said secondary flow heat-transfer the inlet and outlet to said secondary flow heat-transfer passages afforded between alternate plates in said passages are afforded between alternate plates in stack by the said aligned inlet and outlet openings said stack by the said aligned inlet and outlet openextending longitudinally of said stack; ings extending longitudinally of said stack; said transverse corrugation patterns in said series two said transverse corrugation patterns in said series two plates affording secondary flow between said inlets plates affording secondary flow between said inlets and outlets to the longitudinal passages formed by and said outlets to the longitudinal passages formed said aligned openings and with each facing plate of by said aligned openings and with each facing plate of the adjacent series one plate in adjacent pairs prothe adjacent series one plate in adjacent pairs providing transverse corrugations for inciting turbulence in said secondary flow heat transfer passages.

References Cited plates of substantially uniform planar extent and of rela- UNITED STATES PATENTS tively thm material so formed and stacked as to provide heat transfer through said plates to and from a series g i of alternate primary and secondary fluid-flow passages G 0mm formed between alternate plates so stacked 3106243 10/1963 Knudsen 165-167 3,228,464 1/1966 Stein et al. 165-166 said plates having spaced openings therein aligned when stacked to form mlet and outlet to and from ROBERT A. 01E ARY, Primary Examiner one of said series of flow passages in a direction longitudinally of said stacked plates; T. W. STREULE, Assistant Examiner. 

